Image generation system

Abstract

To provide a technique for facilitating the monitoring of the communication states of a plurality of vehicles.SOLUTION: An image generation system 1 includes: on-vehicle devices 12 mounted on a plurality of vehicles, respectively; and a server device 10 that is time-synchronized with the plurality of on-vehicle devices 12 and can communicate with the plurality of on-vehicle devices 12. Each on-vehicle device includes: a packet generation unit that generates a packet containing transmission time; and a transmission control unit that transmits the generated packet to a server device every predetermined unit time. The server device includes: a holding unit that holds the transmitted packet together with reception time when the packet is received; an extraction unit that extracts packets in the same time zone transmitted within a range of the unit time from held packets; a calculation unit that calculates difference between the transmission time and the reception time of the packets as a communication delay time; and an image generation unit that generates a communication delay image based on the communication delay time of the packets in the same time zone.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a technique for imaging the communication states of a plurality of vehicles.

Background Art

[0002] Patent Document 1 discloses an information providing method performed by a server device that provides information for selecting channels for vehicles capable of communicating using a plurality of channels. This server device acquires report data including position information from the vehicles and generates a network information database representing the wireless communication situation for each geographical area.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the number of vehicles to be monitored increases, the report data from the vehicles becomes a large amount, and it is not easy for the administrator to grasp the failure situation from the report data.

[0005] An object of the present invention is to provide a technique for facilitating the monitoring of the communication states of a plurality of vehicles.

Means for Solving the Problems

[0006] To solve the above problems, an image generation system according to an aspect of the present invention includes in-vehicle devices respectively mounted on a plurality of vehicles, and a server device that is time-synchronized with the plurality of in-vehicle devices and can communicate with the plurality of in-vehicle devices. The in-vehicle device has a packet generation unit that generates a packet including a transmission time, and a transmission control unit that transmits the generated packet to the server device every predetermined unit time. The server device has a holding unit that holds the packet received by the transmission control unit together with the reception time, an extraction unit that extracts packets in the same time zone transmitted within the range of the unit time among the held packets, a calculation unit that calculates the difference between the transmission time and the reception time of the extracted packet as a communication delay time, and an image generation unit that generates a communication delay image based on the communication delay time of the packets in the same time zone. The extraction unit extracts packets in the same time zone at the transmission time from the packets accumulated for a predetermined extraction target time at the reception time. The predetermined extraction target time is longer than the unit time.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a technique for facilitating the monitoring of the communication states of a plurality of vehicles.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0009] FIG. 1 is a diagram showing the configuration of the image generation system 1 according to the embodiment. The image generation system 1 includes a server device 10 and an in-vehicle device 12. The in-vehicle device 12 is provided in each of a plurality of vehicles and can perform wireless communication with the server device 10 via a wireless station. Each of the plurality of in-vehicle devices 12 transmits vehicle data such as vehicle status information and position information to the server device 10. In FIG. 1, two in-vehicle devices 12 are transmitting data to the server device 10 respectively, but the actual number of vehicles assumed is in the tens of thousands.

[0010] The server device 10 is provided in a data center and monitors vehicles based on the vehicle data of the in-vehicle device 12. The server device 10 displays the monitoring results to the administrator.

[0011] The server device 10 and the in-vehicle device 12 are time-synchronized using GPS (Global Positioning System). The server device 10 and the in-vehicle device 12 may each obtain the absolute time from an NTP (Network Time Protocol) server and be set to the obtained absolute time.

[0012] FIG. 2 shows the functional configuration of the image generation system 1 according to the embodiment. Various functions of the image generation system 1 can be configured by circuit blocks, memories, and other LSIs in terms of hardware, and can be realized by programs loaded in the memory and the like in terms of software. Therefore, it is understood by those skilled in the art that various functions of the image generation system 1 can be realized in various forms by hardware only, software only, or a combination thereof, and are not limited to any one of them.

[0013] The server device 10 includes a communication unit 20, a holding unit 22, an extraction unit 24, a calculation unit 26, an image generation unit 28, an output control unit 30, a display unit 32, and an estimation unit 34. The in-vehicle device 12 includes a GPS reception unit 40, a detection unit 42, an acquisition unit 44, a packet generation unit 46, and a transmission control unit 48.

[0014] The GPS receiver 40 of the in-vehicle device 12 periodically acquires the current position information of the vehicle with a time stamp using GPS. The GPS receiver 40 functions as a position information acquisition unit that acquires the position information of the vehicle. Note that the position information may be acquired using not only GPS but also another GNSS (Global Navigation Satellite System).

[0015] The detection unit 42 is provided in each in-vehicle device and detects the operating state of the in-vehicle functions. For example, the detection unit 42 detects the operating states of motor devices, steering devices, brake devices, air conditioner devices, headlight devices, short-range wireless communication devices, audio devices, driving assistance functions such as auto cruise, etc. The detection unit 42 may be a driving state detection sensor that detects the driving state of the vehicle.

[0016] The acquisition unit 44 acquires status information indicating the operating state of the in-vehicle functions as a detection result by the detection unit 42. Also, the acquisition unit 44 acquires the current position information of the vehicle from the GPS receiver 40.

[0017] The packet generation unit 46 generates a packet including the acquired status information. The packet generated by the packet generation unit 46 is a UDP heartbeat packet and is transmitted to the server device 10 every unit time. The unit time is, for example, 1 second, but is not limited to 1 second and may be several seconds. Hereinafter, 1 second will be described as the unit time.

[0018] The packet generation unit 46 generates a packet by adding one or more status information to the packet. The status information includes a status ID indicating the type of status and information representing the status. The information representing the status is, for example, "0" and "1", where "0" indicates normal and "1" indicates abnormal. The information representing the status is not limited to two levels and may be three levels or more.

[0019] The packet generation unit 46 includes the transmission time as a timestamp in the packet. The transmission time added to the packet may be described in milliseconds and may be described down to sub-microsecond units. The packet generation unit 46 has software for stamping in sub-microsecond units. With a sub-microsecond timestamp, the server device 10 side can order in units of 1 second or less. As a result, the time resolution on the server device 10 side is improved, and the possibility of identifying the types and causes of troubles can be increased.

[0020] The packet generation unit 46 may add status information and the vehicle's position information to the packet. By including the vehicle's position information in the packet, it becomes possible to grasp the obstacles occurring in the area and their spread.

[0021] The transmission control unit 48 transmits the packet data generated by the packet generation unit 46 to the server device 10 every unit time. Since it is a heartbeat, the transmission control unit 48 does not check whether the packet has reached the server device 10 and only sends it. However, since a packet is transmitted every 1 second, even if one packet does not arrive, the next packet is immediately transmitted. The packet data transmitted from the transmission control unit 48 includes the vehicle ID. That is, the packet data transmitted from the transmission control unit 48 includes vehicle status information, the vehicle's position information, the transmission time, and the vehicle ID.

[0022] The communication unit 20 of the server device 10 receives packet data from a plurality of in-vehicle devices 12 it manages. The server device 10 collects the vehicle information included in the packet data. The holding unit 22 holds and accumulates the received packet data. In the packet data held in the holding unit 22, a timestamp is stamped as the reception time at the reception timing. The holding unit 22 holds the packet data including vehicle status information, the vehicle's position information, the transmission time, and the vehicle ID, and the reception time of the packet data. The holding unit 22 may discard the packet data whose reception time is older than 10 seconds ago.

[0023] The extraction unit 24 extracts the packet data in the same time period that was transmitted within the range of the unit time from the retained packet data. The extraction unit 24 extracts, based on the transmission time included in the packet data, the packet data transmitted from the first time to the second time as the data in the same time period. The difference between the first time and the second time is the unit time, which is 1 second.

[0024] The extraction unit 24 extracts the packets in the same time period from the packets accumulated in a predetermined extraction target time longer than the unit time. That is, the packets to be extracted are those accumulated in a predetermined extraction target time longer than the unit time. For example, the extraction unit 24 extracts, from the packets accumulated by the holding unit 22 for 10 seconds, the packets whose transmission time falls within 1 second. Thereby, the packet data with transmission delay can also be extracted as the packets in the same time period.

[0025] FIG. 3 is a diagram for explaining the packet extraction timing. The horizontal axes shown in FIGS. 3(a) and 3(b) are the same time axis, and FIG. 3(b) shows the extraction process in the next cycle of the extraction process shown in FIG. 3(a).

[0026] As shown in FIG. 3(a), the extraction unit 24 extracts the packets in the same time period at the transmission time from the packets accumulated for 10 seconds at the reception time. That is, the extraction unit 24 distinguishes and extracts the packets accumulated for 10 seconds every 1 second at the transmission time. The information regarding the packet data for each 1 second extracted is output in the image generated by the image generation unit 28 described later.

[0027] In FIG. 3(b), it is executed 5 seconds after the extraction process shown in FIG. 3(a). In this way, packets are extracted from the extraction target of 10 seconds, which is longer than the unit time. The status for 5 seconds overlaps, which is for absorbing the processing delay.

[0028] Return to FIG. 2. The calculation unit 26 calculates, for the packet extracted by the extraction unit 24, the difference between the transmission time and the reception time of the packet as the communication delay time. The communication delay time indicates the arrival time from when the in-vehicle device 12 transmits the packet until it is received by the server device 10.

[0029] The image generation unit 28 generates a communication delay image based on the communication delay time of the packets in the same time period calculated by the calculation unit 26. The image generation unit 28 generates a communication delay image by plotting the calculated communication delay times in distinguishable multiple levels. For example, the image generation unit 28 distinguishes the communication delay time into "normal" and "delay" according to the length of time, and plots with symbols or colors that can distinguish "normal" and "delay" to generate an image.

[0030] The image generation unit 28 generates 10 communication delay images based on the communication delay times extracted every second. The image generation timing by the image generation unit 28 is the same as that of the extraction unit 24, every 5 seconds.

[0031] By imaging, the occurrence of delay anomalies and their spread can be grasped at a glance. By extracting packets in the same time period from the packets accumulated for a predetermined time, the packets with communication delays are included in the analysis results. By the image generation unit 28 generating a communication delay image with color-coding according to the state of the communication delay time, it is easy for the administrator to grasp the delay state by looking at the color.

[0032] FIG. 4 shows the communication delay image generated by the image generation unit 28. In FIG. 4, ■ indicates that the communication delay time is normal, □ indicates the status where the communication delay time is abnormal, and the communication delay state for one second is plotted. The communication delay image is generated by plotting the state of the communication delay time of each vehicle on the map based on the position information of the vehicle. That is, the image generation unit 28 arranges the communication delay time on the map according to the position information of the vehicle to generate a delay image.

[0033] The number of vehicles that can be connected to the server device 10 is expected to reach several million, and it is not easy to monitor a very large number of vehicles. For example, when a disaster occurs and the server device 10 receives a large amount of information indicating abnormalities from each vehicle, it is difficult for the administrator to understand what is happening even after viewing a large number of notifications. In the image generation system 1 of the embodiment, by displaying the communication delay image, the administrator can immediately grasp the area where the communication abnormality has occurred, and can accurately identify disasters and the like that have occurred in the area. Note that the communication delay image may be generated by plotting not only on a map but also in the order of transmission times. Further, the state of the communication delay time may be classified and displayed not only in two stages of normal and abnormal but also in three or more stages.

[0034] Returning to FIG. 2. The image generation unit 28 generates 10 status images every 5 seconds, and thus generates extra images. This is to compensate for processing delays and the like when finally outputting the communication delay image as a video. If a processing delay occurs, the extra-generated images are displayed.

[0035] The output control unit 30 causes the display unit 32 to display the generated communication delay images in chronological order. If there is no processing delay, the output control unit 30 discards and displays the communication delay images for 5 seconds that are extra-generated, but if there is a processing delay, the output control unit 30 displays the surplus communication delay images. The display unit 32 is a display device. Since the administrator can view the communication delay images as a video, the administrator can easily grasp the state affected by the failure.

[0036] The estimation unit 34 analyzes the communication delay images generated by the image generation unit 28 and estimates the state of the failure based on the communication delay images. That is, the estimation unit 34 executes image diagnosis processing, and when the communication delay images are input, outputs information indicating the state of the failure. The estimation unit 34 may estimate the state of the failure using, for example, an image diagnosis model learned using a neural network method. By imaging the communication delay information, the state of the failure can be estimated by image diagnosis. The state of the failure indicates, for example, the magnitude of the local communication delay time, the position or range of the communication delay, etc. in stages.

[0037] FIG. 5 is a flowchart of a process for imaging the communication delay state of a vehicle. The server device 10 and the in-vehicle device 12 are synchronized according to the absolute time (S10). The packet generation unit 46 generates packet data by adding the vehicle status information, the current position information of the vehicle, and the transmission time to the heartbeat packet (S12).

[0038] The transmission control unit 48 transmits the generated packet data to the server device 10 every unit time (S14). The packet data transmitted from the transmission control unit 48 includes the transmission time.

[0039] The holding unit 22 of the server device 10 stamps and holds the received packet data with the reception time and accumulates it (S16). The extraction unit 24 extracts packet data in the same time zone at the transmission time from the accumulated packet data (S18).

[0040] The calculation unit 26 calculates the communication delay time based on the difference between the transmission time and the reception time included in the extracted packet data in the same time zone, and the image generation unit 28 plots the communication delay time calculated from the packets in the same time zone to generate a communication delay image (S20). The output control unit 30 causes the generated communication delay image to be displayed on the display unit 32 (S22). By causing the output control unit 30 to display the communication delay images on the display unit 32 in chronological order, the administrator can view the occurrence status of communication failures in a video and grasp the occurrence of abnormalities and their spread.

[0041] It should be noted that the embodiments are merely illustrative, and those skilled in the art will understand that various modifications are possible for the combination of each component, and such modifications are also within the scope of the present invention.

[0042] In the embodiment, the mode in which the server device 10 collectively processes the vehicle data from the in-vehicle device 12 is shown, but the present invention is not limited to this mode. For example, the server device 10 may execute distributed processing. A distributed server device generates a communication delay image based on the vehicle data of the in-vehicle device 12 assigned regionally, and a central server device combines the communication delay images in the same time zone received from a plurality of distributed server devices. Thereby, the communication delay images for all regions are generated. By performing distributed processing, the processing load can be suppressed.

Explanation of Signs

[0043] 1 Image generation system, 10 Server device, 12 In-vehicle device, 20 Communication unit, 22 Holding unit, 24 Extraction unit, 26 Calculation unit, 28 Image generation unit, 30 Output control unit, 32 Display unit, 34 Estimation unit.

Claims

1. In-vehicle devices respectively mounted on a plurality of vehicles, A server device that is time-synchronized with the plurality of in-vehicle devices and can communicate with the plurality of in-vehicle devices, The in-vehicle device includes: A packet generation unit that generates a packet including a transmission time, A transmission control unit that transmits the generated packet to the server device every predetermined unit time, The server device includes: A holding unit that holds the packet received by the transmission control unit together with the reception time, An extraction unit that extracts packets in the same time zone transmitted within the range of the unit time from the held packets, A calculation unit that calculates the difference between the transmission time and the reception time of the extracted packet as a communication delay time, An image generation unit that generates a communication delay image based on the communication delay times of the packets in the same time zone, The extraction unit extracts packets in the same time zone at the transmission time from the packets accumulated for a predetermined extraction target time at the reception time, The predetermined extraction target time is longer than the unit time, characterized in that it is an image generation system.

2. The image generation system according to claim 1, characterized in that the server device further includes an output control unit that causes the display device to display the communication delay images for each unit time in chronological order.

Images